Agricultural machine having tires of different diameters, and related methods

ABSTRACT

An agricultural machine includes a frame having a tongue hitch for attachment to a towing vehicle, the tongue hitch being oriented along a longitudinal axis inline with the direction of travel. The agricultural machine has an axle mounted to the frame and an arm mounted to the axle. A front spindle is mounted at the front end of the arm with a front tire mounted to the front spindle and a rear spindle is mounted at the rear end of the arm with a rear tire mounted to the rear spindle. The tires are positioned on a same side of the swing arm. The front tire has a different diameter than a diameter of the rear tire.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/050,792, “Planter with Full Tandem Offset Pivot,” filed Jul. 31,2018, which claims the benefit of U.S. Provisional Application No.62/543,832, filed Aug. 10, 2017, the entire disclosures of each of whichare hereby incorporated by reference in their entireties.

FIELD

This invention relates generally to agricultural machines, and moreparticularly to an agricultural machine such as a planter having inlinetandem wheels that have differing sizes/capacity with an offset pivot.

BACKGROUND

Agricultural machines such as planters with a plurality of row units areused to plant seeds upon or in the ground. The agricultural machine iscarried by running gear that have one or more tires that support thatthe weight of the machine in the field. To increase efficiency, plantersare becoming wider and the seed hoppers that feed the row units arebecoming larger. Therefore, the running gear must be designed to supportthese larger weights while minimizing the impact on the field of soilcompaction from the weight.

Typical ways of supporting a planter includes using a long tandemrunning gear. A typical long tandem has a main pivot centered betweenthe tires. Having the main pivot further forward creates an upward hitchweight, limiting hitch options and creating unstable situations. Also,having a main pivot centered between the tires puts the main action ofthe tire further away from the seeding row units, thereby hurtingplanter functionality.

Another option is to use a double-sided tandem with the forward and reartires on differing sides of the running gear. With a double-sidedtandem, the pivot is further back, but this requires the tires to be onopposite sides of the running gear. The weight of the machine istransferred from the tires to the soil and creates a zone in the soilbetween the tires that experiences a pinch point, effectively doublingthe pressure in those areas. Also, the tires, though separate, remainclose together and have deep soil compaction issues. The double-sidedtandem can also limit space for narrow row spacing (rows less than 30inches apart), thereby hurting functionality.

Another option is to use running gear with a large single tire. Theselarge singles take up a valuable space often needed by other planterfunctions. The large singles also potentially cause deep soilcompaction.

It is desirable to have running gear for the agricultural machine thatsupports the increase of product weight that planters are being requiredto carry, while minimizing the impact of this weight in the field. It isfurther desired to maintain implement maneuverability and overallplanter functionality.

BRIEF SUMMARY

In one embodiment, the invention is directed to an agricultural machineconfigured to travel through a field in a direction of travel. Theagricultural machine includes a frame having a tongue hitch forattachment to a towing vehicle, the tongue hitch being oriented along alongitudinal axis L which is generally in line with the direction oftravel. The agricultural machine has at least one set of running gearconfigured to support the frame for movement through the field. Each setof running gear includes an axle mounted to the frame and a swing armpivotably mounted to the axle defining a main pivot axis. The swing armhas a front end and a rear end relative the longitudinal axis with themain pivot axis in a portion located between the front end and the rearend. A front spindle is mounted at the front end of the swing arm with afront tire mounted to the front spindle and a rear spindle is mounted atthe rear end of the swing arm with a rear tire mounted to the rearspindle. The front tire and the rear tire are positioned on a same sideof the swing arm with the rear tire longitudinally behind the front tiresuch that they are in line with each other so as to form an inlinetandem running gear. The front tire has a smaller diameter than adiameter of the rear tire.

These and other features and advantages of this invention are describedin, or are apparent from, the following detailed description of variousexemplary embodiments of the systems and methods according to thisinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features of this invention will becomemore apparent and the invention itself will be better understood byreference to the following description of embodiments of the inventiontaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of an agricultural machine in accordancewith the principles of the present invention;

FIG. 2 is an enlarged perspective view of a running gear portion of theagricultural machine of FIG. 1;

FIG. 3 is a side elevation view of the running gear of FIG. 2; and

FIG. 4 is a top view of the running gear of FIG. 2.

Corresponding reference characters indicate corresponding partsthroughout the views of the drawings.

DETAILED DESCRIPTION

The invention will now be described in the following detaileddescription with reference to the drawings, wherein preferredembodiments are described in detail to enable practice of the invention.Although the invention is described with reference to these specificpreferred embodiments, it will be understood that the invention is notlimited to these preferred embodiments. But to the contrary, theinvention includes numerous alternatives, modifications and equivalentsas will become apparent from consideration of the following detaileddescription.

Referring to FIG. 1, an agricultural machine may include a wheeled cart12, which includes a frame 14 and a tongue hitch 16 for attachment to atractor or towing means (not shown). In the illustrated embodiment, theagricultural machine 10 is a planter 10 for planting row crop seeds. Theframe 14 is supported for movement over the ground with running gear 18,with the running gear 18 including two wheels that are arranged in atandem configuration as explained below. The tongue hitch 16 is orientedalong a longitudinal axis L which is generally in line with thedirection of travel. The agricultural machine 10 may further include atool arm 20 to which is mounted seed delivering elements such as seedhoppers 22 and row units 24 with seed metering discs of conventionaldesign. Although the agricultural machine 10 in the shown embodiments isa planter, any type of agricultural machine may utilize the running gearwith tandem wheel configuration as described herein.

Turning now to FIGS. 2 and 3, each running gear 18 includes an axle 30mounted to the frame 14 at hub 32. A swing arm 34 is pivotably mountedto the axle 30 defining a main pivot axis 30A. In the illustratedembodiment, the swing arm 34 is an elongate body 35 having a front end36 and a rear end 38 with the main pivot axis 30A in a top portion 40located between the front end 36 and the rear end 38. A hole 42 isprovided in the top portion 40 of the body 35 for mounting onto the axle30 with a suitable bearing 44 to allow the swing arm 34 to pivot aboutthe axle 30 to which the swing arm 34 is mounted.

A front axle 46 having a front spindle 46A is provided at the front end36 of the body 35 of the swing arm 34. A front tire 48 is mounted to thefront spindle 46A. A rear axle 50 having a rear spindle 50A is providedat the rear end 38 of the body 35 of the swing arm 34. A rear tire 52 ismounted to the rear spindle 50A. As best seen in FIG. 4, the front tire48 and the rear tire 52 are on the same side of the body 35 of the swingarm 34 with the rear tire 52 longitudinally behind the front tire 48such that they are in line with each other so as to form an inlinetandem running gear 18. It has been found that soil pinching is reduceddue to the tires 48, 52 being on the same side of the swing arm 34 in aninline formation. Desirably, the air pressure of each tire 48, 52 ismaintained substantially the same.

According to the invention, the front tire 48 has a smaller diameterthan a diameter of the rear tire 52. As best seen in FIG. 4, the swingarm 34 is configured such that a longitudinal distance A between themain pivot axis 30A and the front axle 46 is greater than a distance Bbetween the main pivot axis 30A and the rear axle 50, such that thetires 48, 52 are offset from the main pivot axis 30A. As would beunderstood by one skilled in the art, since the rear tire 52 has alarger diameter than the front tire 48, the rear tire 52 will also havea larger contact surface area or footprint with the ground than that ofthe front tire 48. Desirably, the differing sizes in tires 48, 52 issuch that the resultant vertical load on the ground from the rear tire52 is about 125-175% of the vertical load of the front tire 48. With theair pressures in the front and rear tires 48, 52 being substantially thesame, the variation of the vertical load allows the front and rear tires48, 52 to have substantially equal ground pressure values. Thelongitudinal distance A between the main pivot axis 30A and the frontaxle 46 is desirably about 125-175% of the distance B between the mainpivot axis 30A and the rear axle 50, and more desirably, about 150% ofthe distance. The larger rear tire 52 provides advantages in rollingover and/or through obstacles due to its larger size. Also, the fronttire 48 is smaller due to limited space on the agricultural machine 10.Offsetting the main pivot axis 30A by using a front tire 48 and reartire 52 having different tire sizes and maintaining constant flotationbetween these two tires, allows for the main weight (i.e., the center ofgravity) of the agricultural machine 10 to be in front of the main pivotaxis 30A, thereby keeping downward weight on the hitch of the towingtractor.

An agricultural machine 10 with the tandem running gear 18 mounted toeach of its axles 30 is better equipped to reduce deep soil compactionand provide improved stability during travel of the agricultural machine10. The swing arm 34 with tandem tires 48, 52 requires less space than asingle larger tire and brings the main action of the tire closer to theseeding row. As the swing arm 34 may pivot about the axle 30 on which itis mounted, at least one of the front tire 48 and the rear tire 52mounted on the swing arm 34 may remain in contact with the ground duringtravel over and/or through obstacles, thereby improving the travel ofthe agricultural machine over and through obstacles.

The foregoing has broadly outlined some of the more pertinent aspectsand features of the present invention. These should be construed to bemerely illustrative of some of the more prominent features andapplications of the invention. Other beneficial results can be obtainedby applying the disclosed information in a different manner or bymodifying the disclosed embodiments. Accordingly, other aspects and amore comprehensive understanding of the invention is obtained byreferring to the detailed description of the exemplary embodiments takenin conjunction with the accompanying drawings.

1. An agricultural machine comprising: a frame defining a longitudinalaxis and having a tongue hitch configured for attachment to a towingvehicle; an axle mounted to the frame; an arm having a front end and arear end relative the longitudinal axis of the frame and a first sidegenerally parallel the longitudinal axis, wherein the arm is mounted tothe axle between the front end and the rear end; a front spindle mountedto the first side of the front end of the arm; a rear spindle mounted tothe first side of the rear end of the arm; a front tire having a firstdiameter mounted to the front spindle; and a rear tire having a seconddiameter mounted to the rear spindle, wherein the second diameter isdifferent from the first diameter.
 2. The agricultural machine of claim1, wherein the agricultural machine comprises a planter.
 3. Theagricultural machine of claim 1, further comprising a bearing, whereinthe arm is mounted to the axle with the bearing such that the arm canpivot about the axle.
 4. The agricultural machine of claim 1, whereinthe arm is configured such that a longitudinal distance A between theaxle and the front spindle is greater than a longitudinal distance Bbetween the axle and the rear spindle.
 5. The agricultural machine ofclaim 4, wherein the longitudinal distance A between the axle and thefront spindle is between 125% and 175% of the distance B between theaxle and the rear spindle.
 6. The agricultural machine of claim 1,wherein an axis of rotation of the front tire longitudinally leads theaxle and an axis of rotation of the rear tire longitudinally trails theaxle.
 7. The agricultural machine of claim 1, wherein the front tire andthe rear tire are pressurized to a common air pressure.
 8. Theagricultural machine of claim 1, wherein a center of gravity of theagricultural machine longitudinally leads the axle.
 9. The agriculturalmachine of claim 1, wherein the rear tire longitudinally trails thefront tire.
 10. The agricultural machine of claim 1, wherein the seconddiameter is larger than the first diameter.
 11. The agricultural machineof claim 1, wherein vertical load on the ground from the rear tire isabout 125-175% of a vertical load on the ground from the front tire. 12.The agricultural machine of claim 1, wherein the frame carries a toolarm, and wherein a plurality of row units are mounted to tool arm. 13.The agricultural machine of claim 12, wherein each row unit of theplurality comprises at least one seed metering disc.
 14. Theagricultural machine of claim 1, further comprising at least one seedhopper carried by the frame.
 15. The agricultural machine of claim 1,wherein the axle is mounted perpendicular to the longitudinal axis. 16.A method of working an agricultural field, the method comprising: towinga vehicle through the agricultural field, the vehicle comprising: aframe having a longitudinal axis; an axle mounted to the frame; an armhaving a front end and a rear end relative the longitudinal axis of theframe and a first side generally parallel the longitudinal axis, whereinthe arm is mounted to the axle between the front end and the rear end; afront spindle mounted to the first side of the front end of the arm; arear spindle mounted to the first side of the rear end of the arm; afront tire having a first diameter mounted to the front spindle; and arear tire having a second diameter mounted to the rear spindle, whereinthe second diameter is different from the first diameter; maintaining anair pressure in the front tire to be substantially equal to an airpressure in the rear tire.
 17. The method of claim 16, furthercomprising maintaining a center of gravity of the vehicle longitudinallyleading the axle.
 18. The method of claim 16, further comprisingmaintaining at least one of the front tire or the rear tire in groundcontact as the vehicle is towed over obstacles in the agriculturalfield.
 19. The method of claim 16, further comprising pivoting the armrelative to the axle.
 20. The method of claim 16, wherein towing avehicle through the agricultural field comprises pulling the vehiclethrough the agricultural field with a tractor.